/*
Copyright (c) 2011, Jeffrey Kunkel
All rights reserved.

Redistribution and use in source and binary forms, with or without 
modification, are permitted provided that the following conditions 
are met:

Redistributions of source code must retain the above copyright notice, 
this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, 
this list of conditions and the following disclaimer in the documentation 
and/or other materials provided with the distribution.
Neither the name of the Jeffrey Kunkel nor the names of its contributors 
may be used to endorse or promote products derived from this software 
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 
THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef PRODUCER_CONSUMER_H_
#define PRODUCER_CONSUMER_H_

#include <boost/interprocess/sync/interprocess_semaphore.hpp>
#include <boost/thread.hpp>
#include <list>

template< typename Data, typename alloc = std::allocator<Data> >
class ProduceConsume {
   //Non-copyable
   ProduceConsume(const ProduceConsume &);
   ProduceConsume &operator=(const ProduceConsume &);
protected:
  boost::interprocess::interprocess_semaphore produce_consume;
  mutable boost::mutex block_que;
  std::list<Data, alloc> que;
public:
  ProduceConsume() : produce_consume(0) { }
  void produce( const Data & d ) {
    block_que.lock();
      que.push_back(d);
    block_que.unlock();

    produce_consume.post();
  }
  void produce_quickly( const Data & d ) {
    block_que.lock();
      que.push_front(d);
    block_que.unlock();

    produce_consume.post();
  }
  Data consume() {
    produce_consume.wait();

    Data d;
    block_que.lock();
      d = que.front();
      que.pop_front();
    block_que.unlock();
    return d;
  }
  bool try_consume(Data & d) {
    bool r;
    r = produce_consume.try_wait();
    if( r ) {
      block_que.lock();
        d = que.front();
        que.pop_front();
      block_que.unlock();
    }
    return r;
  }

  size_t size() const {
    block_que.lock();
      size_t sz = que.size();
    block_que.unlock();
    return sz;
  }
};

#endif
